1. Field of the Invention
The present invention relates to a method and system of smart detection and recovery, and more particularly, to a method and system of smart detection and recovery that are applied in a network environment to detect whether a monitored device has changed its original IP address at an early time so that reconnection can be made to recover services as early as possible.
2. Description of the Prior Art
Deployment of networks, no matter in enterprises, organizations, campuses or in common houses, has become very developed. Accordingly, numerous devices for providing services are disposed in these network environments. For purpose of convenience, most of the networks adopt the Dynamic Host Configuration Protocol (DHCP) for configuration of network addresses. However, when network addresses used by these devices for providing services experience a change due to some reasons, interruption of the services will occur.
As the number of conventional network addresses has become insufficient for use, network address translation (NAT) is often adopted in many environments to increase the number of devices allowed to use. When such devices deployed in the NAT network environment desire to provide a service, a port forwarding operation becomes inevitable. However, once such a device changes its original network address, a trouble will be caused to both the service providers and the service users.
To solve this problem, many different methods have been proposed. As one of these methods, Dynamic Domain Name Service (Dynamic DNS) may be suitable for some environments, but when operating in network environments adopting NAT, it would become almost useless.
Taking a VoIP (Voice over IP) communication environment shown in FIG. 1 as an example, the Response Point plan has been proposed by Microsoft® as a VoIP application in order to ease the difficulty in setting VoIP. The purpose is to, by means of a humanistic design and by using an automatic server, a VoIP phone and a VoIP gateway together, eliminate the trouble caused by changing settings of conventional telephone switch networks, thereby reducing cost of deploying a telephone network in an enterprise environment and taking full advantage of the cost-saving nature of VoIP communication. Moreover, because the Response Point telephone network is declared to be easy to deploy, all devices used in such a network adopt DHCP for self-setting.
In the Response Point telephone network, there exists a base unit that plays the role of an SIP (Session Initiation Protocol) server. Apart from playing the role of an SIP server, the base unit also has to serve the functions of voice recognition, voice mail and some of service functions specific to Response Point. Telephones and gateways intended to use the VoIP services all have to register with this base unit in order to exchange messages through SIP. Although it seems to be reasonable, such a network architecture has a potential risk because once an error or crash occurs to the base unit, it would mean failure of the whole telephone network, which would impose a direct impact on the enterprise. For this problem, enabling the base unit to monitor itself by means of a certain software program (e.g., WatchDog®) may be a good solution. Unfortunately, once the base unit is rebooted after occurrence of an error, a change of the network address may make the telephones and gateways in the network unaware of the change in address of the base unit, causing failure to utilize the telephone functions. Hence, improvement still has to be made.
Taking a home IP sharing communication environment shown in FIG. 2 as an example, as the number of conventional network addresses has become not enough for use, home users who require connecting several computers to the network at the same time mostly purchase an IP sharing switch to achieve this goal. Most of the commercially available IP sharing switches for home use integrate diversified functions together, e.g., functions of an AP (Access Point), Dynamic DNS, access restrictions, and the like. When a user desires to provide a service in such a network environment, the Dynamic DNS provided by the IP sharing switch allows the user to not worry about the problem of whether the network address is fixed, and what left to be done is configuration of the service devices within the IP sharing network.
Usually, IP sharing provides the function of Port Forwarding so that the user can access a designated device within the internal network via a specific port that connects with an external address. However, this also causes the problem that a device for providing services might fail to be connected normally due to change of the network address. Accordingly, improvement still has to be made thereon.